achs-7121/7122/7123 fully integrated, hall effect-based ... · data sheet broadcom achs-712x-ds101...

Data Sheet

Broadcom ACHS-712x-DS101February 28, 2018

OverviewThe Broadcom® ACHS-7121/7122/7123 product series is a fully integrated Hall Effect-based isolated linear current sensor device family designed for AC or DC current sensing in industrial, commercial, and communications systems. Each of the ACHS-7121/7122/7123 consists of a precise, low-offset, linear Hall circuit with a copper conduction path located near the surface of the die. Applied current flowing through this copper conduction path generates a magnetic field that the Hall IC converts into a proportional voltage. Device accuracy is optimized through the close proximity of the magnetic signal to the Hall transducer.

A precise, proportional voltage is provided by the low-offset, chopper-stabilized CMOS Hall IC, which is programmed for accuracy after packaging. The output of the device has a positive slope (>VOUT(Q)) when an increasing current flows through the primary copper conduction path (from pins 1 and 2, to pins 3 and 4), which is the path used for current sampling.

The internal resistance of this conductive path is 0.7 mΩ typical, providing low-power loss. The terminals of the conductive path are electrically isolated from the signal leads (pins 5 through 8). This performance is delivered in a compact, surface mountable, SO-8 package that meets worldwide regulatory safety standards.

Features Wide Operating Temperature: –40ºC to 110ºC Primary conductor resistance: 0.7 mΩ typ. Sensing current range: ±10A, ±20A, and ±30A Output sensitivity: 66 to 185 mV/A Output voltage proportional to AC or DC currents Ratiometric output from supply voltage Single supply operation: 5.0V Low-noise analog signal path Device bandwidth is set via FILTER pin:

80 kHz typ. Bandwidth with 1 nF filter capacitor Factory-trimmed for accuracy Extremely stable output offset voltage Near zero magnetic hysteresis Typical total output error of ±1.5% >25 kV/μs Common-Mode Transient Immunity Small footprint, low-profile SO-8 package Worldwide Safety Approval: UL, CSA:

Isolation Voltage 3 kVRMS, 1 minute

Applications Low-power inverter current sensing Motor phase and rail current sensing Solar inverters Chargers and Converters Switching Power Supplies

Part Number Current Range SensitivityACHS-7121 ±10A 185 mV/AACHS-7122 ±20A 100 mV/AACHS-7123 ±30A 66 mV/A

ACHS-7121/7122/7123Fully Integrated, Hall Effect-Based Linear Current Sensor IC with 3 kVRMS Isolation and Low-Resistance Current Conductor

CAUTION! It is advised that normal static precautions be taken in handling and assembly of this component to prevent damage and/or degradation which may be induced by ESD. The components featured in this data sheet are not to be used in military or aerospace applications or environments.

Broadcom ACHS-712x-DS1012

ACHS-7121/7122/7123 Data Sheet Fully Integrated, Hall Effect-Based Linear Current Sensor IC with 3 kVRMS Isolation and

Low-Resistance Current Conductor

Functional Diagram

NOTE: The connection of 1 μF bypass capacitor between pins 8 and 5 is recommended.

Pin Description

Typical Application CircuitA typical application circuit for the ACHS-7121/7122/7123 product series consists of a bypass capacitor and a filter capacitor as additional external components. On the input side, pins 1 and 2 are shorted together and pins 3 and 4 shorted together. The output voltage is directly measured from the VOUT pin.

Pin Pin Name Description Pin Pin Name Description1 IP+ Terminals for current being sampled; fused

internally 8 VDD Supply voltage relative to GND

2 IP+ 7 VOUT Output Voltage

3 IP– Terminals for current being sampled; fused internally

6 FILTER Filter pin to set bandwidth

4 IP– 5 GND Output side ground

I

P+

P+

IIIP–

P–

VDD

VOUT

FILTERGND

1

2

3

4

8

7

6

5

VDD

VOUT

FILTERGND

5V

CBYPASS

CF

OUTPUTI

P+

P+IP+IIIP–

IP–P–




Ordering Information

To order, choose a part number from the part number column and combine with the desired option from the option column to form an order entry.

Example: Select ACHS-7122-500E to order product of ±20A, surface-mount package in tape and reel packaging and RoHS compliance. Contact your Broadcom sales representative or authorized distributor for information.

Option data sheets are available. Contact your Broadcom sales representative or authorized distributor for information.

Part Number Current Range

Option

Package Surface Mount Tape and ReelUL 3 kVRMS1 min. rating Quantity

(RoHS) Compliant

ACHS-7121 ±10A -000E SO-8 X X 100 per tube-500E X X X 1500 per reel

ACHS-7122 ±20A -000E X X 100 per tube-500E X X X 1500 per reel

ACHS-7123 ±30A -000E X X 100 per tube-500E X X X 1500 per reel




Package Outline Drawing

ACHS-7121/7122/7123 SO-8 Package

Dimensions in millimeters (inches).

NOTE:Lead Coplanarity = 0.100 mm (0.004 inches) max.Floating lead protrusion = 0.254 mm (0.010 inches) max.Mold Flash on each side = 0.127 mm (0.005 inches) max.

Recommended Pb-Free IR ProfileRecommended reflow condition as per JEDEC Standard, J-STD-020 (latest revision). Non-halide flux should be used.

1 2 3 4

8 7 6 5

0.457 (0.018)

1.27 (0.050)

3.937 (0.155 )

5.080 (0.200 ) +0.010

–0.005

+0.254 –0.127

+0.010 –0.005

+0.254 –0.127

1.908 ±0.127 (0.075 ±0.005)

7°

0.254 ±0.050 (0.010 ±0.002)

0.381±0.127 (0.015 ±0.005)

0.800 ±0.127 (0.031 ±0.005)

6.000 (0.236 ) +0.010

–0.005

+0.254 –0.127

0° to 7°

0.64 (0.025)

7.49 (0.295)

1.9 (0.075)

0.203 ±0.100 (0.008 ±0.004)

XXXXYYWW

EEE RoHSCompliance

Datecode

Lot ID

Part Number




Regulatory InformationThe ACHS-7121/7122/7123 is approved by the following organizations:

Insulation and Safety Related Specifications

Absolute Maximum Rating

UL/cULUL 1577, component recognition program up to VISO = 3000VRMS. Approved under CSA Component Acceptance Notice #5.

Parameter Symbol Value Unit ConditionsMinimum External Air Gap (External Clearance)

L(101) 4.0 mm Measured from input terminals to output terminals, shortest distance through air.

Minimum External Tracking (External Creepage)

L(102) 4.0 mm Measured from input terminals to output terminals, shortest distance path along body.

Minimum Internal Plastic Gap (Internal Clearance)

— 0.05 mm Through insulation distance, conductor to conductor, usually the direct distance between the primary input conductor and detector IC.

Tracking Resistance (Comparative Tracking Index)

CTI >175 V DIN IEC 112/VDE 0303 Part 1.

Isolation Group — IIIa — Material Group (DIN VDE 0110, 1/89, Table 1).

Parameter Symbol Min. Max. Unit Test ConditionsStorage Temperature TS –55 125 °C —

Ambient Operating Temperature TA –40 110 °C —

Junction Temperature TJ — 150 °C —

Primary Conductor Lead Temperature TL — 150 °C Pins 1, 2, 3, or 4

Supply Voltages VDD –0.5 8.0 V —

Output Voltage VOUT –0.5 VDD + 0.5 V —

Output Current Source IOUT(source) — 10 mA TA = 25°C

Output Current Sink IOUT(sink) — 10 mA TA = 25°C

Overcurrent Transient Tolerance IP — 100 A 1 pulse, 100 ms; TA = 25°C

Input Power Dissipation PIN — 900 mW TA = 25°C

Output Power Dissipation POUT — 90 mW TA = 25°C




Recommended Operating Conditions

Common Electrical SpecificationsUnless otherwise stated, all minimum/maximum specifications are over recommended operating conditions, CF = 1 nF. All typical values are based on TA = 25°C, VDD = 5.0V, CF = 1 nF.

Electrical Specifications

ACHS-7121Unless otherwise stated, all minimum/maximum specifications are over recommended operating conditions, CF = 1 nF. All typical values are based on TA = 25°C, VDD = 5.0V, CF = 1 nF.

Parameter Symbol Min. Max. UnitAmbient Operating Temperature TA –40 110 °C

Supply Voltage VDD 4.5 5.5 V

Output Capacitive Load CLOAD — 10 nF

Output Resistive Load RLOAD 4.7 — kΩ

Input Current Range ACHS-7121 IP –10 10 AACHS-7122 –20 20 AACHS-7123 –30 30 A

Parameter Symbol Min. Typ. Max. Unit Test Condition Fig. NoteSupply Current IDD — 13 15 mA VDD = 5V, output

open5,6 1

Primary Conductor Resistance RPRIMARY — 0.7 — mΩ — — 1

Zero Current Output Voltage VOUT(Q) — VDD/2 — V Bidirectional, IP=0A 2 1

Input Filter Resistance RF(INT) — 1.6 — kΩ — — 1

Bandwidth BW — 80 — kHz –3 dB — 1Rise Time tr — 4 — μs — 10 1

Power-on Time tPO — 21 — μs — 8 1

Common Mode Transient Immunity CMTI 25 — — kV/us VCM = 1000V — 3

Parameter Symbol Min. Typ. Max. Unit Test Conditions Fig. NoteOptimized Input Current Range IP –10 — 10 A — 7 4

Sensitivity Sens — 185 — mV/A –10A ≤ IP ≤ 10A 1 1

Sensitivity Error ESENS –3 — 3 % TA = 25°C, VDD = 5V 1 1

Sensitivity Slope ΔSens — –0.04 — mV/A/°C TA = –40°C to 25°C 1 1

Sensitivity Slope ΔSens — 0.01 — mV/A/°C TA = 25°C to 110°C 1 1

Zero Current Output Error VOE –30 — 30 mV TA = 25°C 2 1

Zero Current Output Error Slope ΔVOE — –0.03 — mV/°C TA = –40°C to 25°C 2 1






Zero Current Output Error Slope ΔVOE — 0.06 — mV/°C TA = 25°C to 110°C 2 1

Output Noise VN(RMS) — 7.8 — mV BW = 2 kHz 9 10

Nonlinearity NL — 0.27 — % — 3 2Total Output Error ETOT — ±1.5 — % — 4 5

Sensitivity Error Lifetime Drift ESENS_DRIFT — ±2 — % — — 1

Total Output Error Lifetime Drift ETOT_DRIFT — ±2 — % — — 1







Zero Current Output Error Slope ΔVOE — 0.01 — mV/°C TA = –40°C to 25°C 2 1












Zero Current Output Error Slope ΔVOE — 0.01 — mV/°C TA = –40°C to 25°C 2 1


Parameter Symbol Min. Typ. Max. Unit Test Conditions Fig. Note




Package Characteristics

NOTE:1. Refer to the Definition of Electrical Characteristics in the Application Section of the data sheet.2. Nonlinearity is defined as half of the peak-to-peak output deviation from the best-fit line, expressed as a

percentage of the full-scale output voltage. See the Definition of Electrical Characteristics in the Application Section of the data sheet for the complete definition and formula.

3. Common Mode Transient Immunity is tested by applying a fast rising/falling voltage pulse across pin 4 and GND (pin 5). The output glitch observed is less than 0.2V from the average output voltage for less than 1 μs.

4. Device may be operated at higher primary current levels, IP, provided that the Maximum Junction Temperature, TJ(MAX) is not exceeded.

5. Total output error in percentage is the difference between the measured output voltage at maximum input current (IPMAX) and the ideal output voltage at IPMAX divided by the ideal output voltage at IPMAX. The Total Output Error typical value is based on total output error measured at the point of product release.

6. In accordance with UL 1577, each device is proof tested by applying an insulation test voltage ≥3600VRMS for 1 second.

7. The Input-Output Momentary Withstand Voltage is a dielectric voltage rating that should not be interpreted as an input-output continuous voltage rating.

8. This is a two-terminal measurement: pins 1 through 4 are shorted together and pins 5 through 8 are shorted together.

9. The Broadcom evaluation board has 300 mm2 (total area including top and bottom copper) of 2 oz. copper connected to pins 1 and 2 and pins 3 and 4. Refer to the application section for additional information on thermal characterization.

10. Output Noise is the noise level of the ACHS-7121/7122/7123 expressed in root mean square (RMS) voltage.





Parameter Symbol Min. Typ. Max. Unit Test Condition NoteInput-Output Momentary Withstand Voltage VISO 3000 — — VRMS RH < 50%, t = 1 min., TA = 25°C 6, 7, 8

Resistance (Input-Output) RI-O — 1014 — Ω VI-O = 500VDC 8

Capacitance (Input-Output) CI-O — 1.3 — pF f = 1 MHz 8

Junction-to-Ambient Thermal Resistance (due to Primary Conductor)

Rθ12 — 55 — °C/W Based on the Broadcom evaluation board

9

Junction-to-Ambient Thermal Resistance (due to IC)

Rθ22 — 27 — °C/W Based on the Broadcom evaluation board

9

Parameter Symbol Min. Typ. Max. Unit Test Conditions Fig. Note




Typical Performance Plots All typical plots are based on TA = 25°C, VDD = 5V, CF = 1 nF, unless otherwise stated.

Figure 1: Sensitivity vs. Temperature Figure 2: Zero Current Output Voltage vs. Temperature

50

75

100

125

150

175

200

–40 –20 0 20 40 60 80 100 120

Sens

itivi

ty (S

ens)

– m

V/A ACHS-7121

ACHS-7122

ACHS-7123

Temperature (TA) – °C

2.485

2.490

2.495

2.500

2.505

2.510

2.515

–40 –20 0 20 40 60 80 100 120

ACHS-7121

ACHS-7122

ACHS-7123

Temperature (TA) – °CZe

ro C

urre

nt O

utpu

t Vol

tage

(VO

UT(

Q))

– V

Figure 3: Nonlinearity vs. Temperature Figure 4: Total Output Error at IPMAX vs. Temperature

0.000.020.040.060.080.100.120.140.160.180.200.220.240.260.280.30

–40 –20 0 20 40 60 80 100 120

Non

linea

rity

(NL)

– %

Temperature (TA) – °C

ACHS-7121

ACHS-7122

ACHS-7123–8.0%

–6.0%

–4.0%

–2.0%

0.0%

2.0%

4.0%

6.0%

8.0%

–40 –20 0 20 40 60 80 100 120Temperature (TA) – °C

ACHS-7121

ACHS-7122

ACHS-7123

Tota

l Out

put E

rror

(ETO

T) –

%




Figure 5: Supply Current vs. Temperature Figure 6: Supply Current vs. Supply Voltage

12.6

12.8

13.0

13.2

13.4

13.6

13.8

–40 –20 0 20 40 60 80 100 120Temperature (TA) – °C

Supp

ly C

urre

nt (I

DD) –

mA

11.0

11.5

12.0

12.5

13.0

13.5

14.0

14.5

3 3.5 4 4.5 5 5.5 6Supply Voltage (VDD) – V

110°C

25°C

–40°C

Supp

ly C

urre

nt (I

DD) –

mA

Figure 7: Output Voltage vs. Input Current Figure 8: Power On Time vs. External Filter Capacitance

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

–30 –20 –10 0 10 20 30Input Current (IP) – A

ACHS-7121

ACHS-7122

ACHS-7123

Out

put V

olta

ge (V

OU

T) –

V

0

20

40

60

80

100

0 2 4 6 8 10

IP = IP(max)

External Filter Capacitance (CF) – nF

Pow

er O

n Ti

me

(tPO) –

s

Figure 9: Output Noise vs. External Filter Capacitance Figure 10: Rise Time vs. External Filter Capacitance

0.1

1

10

0.01 0.1 1 10 100

Out

put N

oise

(VN

(RM

S)) –

mV


ACHS-7121

ACHS-7122

ACHS-7123

0

5

10

15

20

25

30

0 2 4 6 8 10

Ris

e Ti

me

(tR) –

s


IP = IP(max)




Definition of Electrical CharacteristicsThe ACHS-7121/7122/7123 product series is a Hall Effect current sensor that outputs an analog voltage proportional to the magnetic field intensity caused by the current flowing through the input primary conductor. Without the magnetic field, the output voltage is half of the supply voltage. The sensor can detect both DC and AC current.

Ratiometric OutputThe output voltage of the ACHS-7121/7122/7123 series is ratiometric or proportional to the supply voltage. The sensitivity (Sens) of the device and the quiescent output voltage changes when there is a change in the supply voltage (VDD). For example, when the VDD is increased by 10% from 5V to 5.5V in the ACHS-7122, the quiescent output voltage changes from 2.5V to 2.75V and the sensitivity also changes from 100 mV/A to 110 mV/A.

SensitivityThe output sensitivity (Sens) is the ratio of the output voltage (VOUT) over the input current (IP) flowing through the primary conductor. It is expressed in mV/A. When an applied current flows through the input primary conductor, it generates a magnetic field which the Hall IC converts into a voltage. The proportional voltage is provided by the Hall IC which is programmed in the factory for accuracy after packaging. The output voltage has a positive slope when an increasing current flows through pins 1 and 2 to pins 3 and 4. Sensitivity Error (ESENS) is the difference between the measured Sensitivity and the Ideal Sensitivity expressed as a percentage (%).

NonlinearityNonlinearity is defined as half of the peak-to-peak output deviation from the best-fit line (BFL), expressed as a percentage of the full-scale output voltage. The full-scale output voltage is the product of the sensitivity (Sens) and full scale input current (IP).

Figure 11: Nonlinearity Calculation

Zero Current Output VoltageThis is the output voltage of ACHS-7121/7122/7123 when the primary current is zero. Zero current output voltage is half of the supply voltage (VDD/2).

Zero Current Output ErrorThis the voltage difference between the measured output voltage and the ideal output voltage (VDD/2) when there is no input current to the device.

Total Output ErrorTotal output error in percentage is the difference between the measured output voltage at maximum input current (IPMAX) and the ideal output voltage at IPMAX divided by the ideal output voltage at IPMAX.

Power-On TimeThis is the time required for the internal circuitry of the device to be ready during the ramping of the supply voltage. Power on time is defined as the finite time required for the output voltage to settle after the supply voltage reached its recommended operating voltage.

NL(%) = [(Max from BFL – Min from BFL) / 2]

Sens X full scale IP

× 100%

IP(MIN)

IP(MAX)

VOUT

BFL

Maxfrom BFL

Minfrom BFL

full scale IP)

ETOT (%) = Measured VOUT @ IPMAX – Ideal VOUT @ IPMAX

Ideal VOUT @ IPMAX

× 100%




FILTER PinThe ACHS-7121/7122/7123 has a FILTER pin for improving the signal-to-noise ratio of the device. This eliminates the need for an external RC filter for the VOUT pin of the device, which can cause attenuation of the output signal. A ceramic capacitor, CF, can be connected between the FILTER pin to GND.

Application Information

PCB LayoutThe design of the printed circuit board (PCB) should follow good layout practices, such as keeping bypass capacitors close to the supply pin and use of ground and power planes. A bypass capacitor must be connected between pins 5 and 8 of the device. The layout of the PCB can also affect the common-mode transient immunity of the device due to stray capacitive coupling between the input and output circuits. To obtain maximum common-mode transient immunity performance, the layout of the PCB should minimize any stray coupling by maintaining the maximum possible distance between the input and output sides of the circuit and ensuring that any ground or power plane on the PCB does not pass directly below or extend much wider than the body of the device.

Land Pattern for 4 mm Board CreepageFor applications that require PCB creepage of 4 mm between input and output sides, the land pattern in Figure 12 can be used.

Figure 12: Land Pattern for 4 mm Creepage

Effect of PCB Layout on SensitivityThe trace layout on the input pins of ACHS-7121/7122/7123 affects the sensitivity. It is recommended that the PCB trace connection to the input pins covers the pins fully, as shown in Figure 13.

Figure 13: Recommended Trace Layout on Input Pins

0.64(0.025)

1.50 (0.059)

7.1 (0.280)

IP- IP+

PCBTRACE

PCBTRACE




When the connection to the input pin only covers the vertical portion of the input pin, there is a sensitivity variation of about –0.6% versus recommended PCB trace layout (as shown in Figure 14).

Figure 14: Vertical Portion Connection

When the connection to the input pin only covers the horizontal portion of the input pin, there is a sensitivity variation of about +1.2% versus recommended PCB trace layout (as shown in Figure 15).

Figure 15: Horizontal Portion Connection

Thermal ConsiderationThe evaluation board used in the thermal characterization is shown in Figure 16. Inputs IP+ and IP– are each connected to input plane of 2 oz. copper with 300 mm2 total area (including top and bottom planes). The output side GND is connected to a ground plane of 2 oz. copper with 460 mm2 total area (including top and bottom planes). The 2 oz. copper enables the board to conduct higher current and achieve good thermal distribution in a limited space.

Figure 16: Broadcom Evaluation Board—Top Layer

Figure 17: Broadcom Evaluation Board—Bottom Layer

IP- IP+

PCBTRACE

PCBTRACE

IP- IP+

PCBTRACE

PCBTRACE

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Copyright © 2018 by Broadcom. All Rights Reserved.

The term “Broadcom” refers to Broadcom Limited and/or its subsidiaries. For more information, please visit www.broadcom.com.

Broadcom reserves the right to make changes without further notice to any products or data herein to improve reliability, function, or design. Information furnished by Broadcom is believed to be accurate and reliable. However, Broadcom does not assume any liability arising out of the application or use of this information, nor the application or use of any product or circuit described herein, neither does it convey any license under its patent rights nor the rights of others.

achs-7121/7122/7123 fully integrated, hall effect-based ... · data sheet broadcom achs-712x-ds101...

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